<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <!-- 
        display作用：
        1.改变元素的显示类型

        元素分类：
        1.块级元素：div h1 p ul ol li dl dt dd
        2.行内元素: span a strong em i u s
        3.行内块元素: img input

    -->

    <style>
        .box {
            width: 700px;
            height: 700px;
            background-color: pink;
            display: none;
        }

        .box1 {
            width: 100px;
            height: 100px;
            background-color: red;
            display: block;
        }

        .box2 {
            width: 100px;
            height: 100px;
            background-color: green;
            visibility: hidden;
        }

        .box3 {
            width: 100px;
            height: 100px;
            background-color: green;
            opacity: 0.5;
        }

        .box4 {
            width: 50px;
            height: 15px;
            border: 2px solid red;
            overflow: hidden;
        }
    </style>
</head>

<body>
    <div class="box">box</div>
    <div class="box2">box2</div>
    <a class="box1">box1</a>
    <div class="box3">box3</div>
    <div class="box4">box4</div>
    <a class="box1">box1</a>
</body>

</html>